SmogRank / Senegal / Saint-Louis

Air quality in Saint-Louis

Saint-Louis, Senegal. PM2.5 from 3 low-cost sensors, updated hourly.

241.1µg/m³
Hazardous

Latest hour (08:00 UTC), 16.1× the WHO 24-hour guideline.

Rank, worst first

24 hours–not enough data
7 days#189of 2,330, at 17.8 µg/m³
30 days#29of 2,324, at 44.5 µg/m³
This year–not enough data

Why it ranks here

Unusually bad for Saint-Louis. The last 7 days averaged 17.8 µg/m³, about 2.1× its typical day (8.4). A jump like this usually has a short-lived cause: likely smoke from fires, dust, or stagnant weather trapping local emissions.

Based on Saint-Louis's own measurements; causes are the usual kinds for a pattern like this, not a confirmed source.

The last 12 months, day by day

1102031Oct 2025NovDecJan 2026FebMarAprMayJunJulAugSep2025-10-01: no data2025-10-02: no data2025-10-03: no data2025-10-04: no data2025-10-05: no data2025-10-06: no data2025-10-07: no data2025-10-08: no data2025-10-09: no data2025-10-10: no data2025-10-11: no data2025-10-12: no data2025-10-13: no data2025-10-14: no data2025-10-15: no data2025-10-16: no data2025-10-17: no data2025-10-18: no data2025-10-19: no data2025-10-20: no data2025-10-21: no data2025-10-22: no data2025-10-23: no data2025-10-24: no data2025-10-25: no data2025-10-26: no data2025-10-27: no data2025-10-28: no data2025-10-29: no data2025-10-30: no data2025-10-31: no data2025-11-01: no data2025-11-02: no data2025-11-03: no data2025-11-04: no data2025-11-05: no data2025-11-06: no data2025-11-07: no data2025-11-08: no data2025-11-09: no data2025-11-10: no data2025-11-11: no data2025-11-12: no data2025-11-13: no data2025-11-14: no data2025-11-15: no data2025-11-16: no data2025-11-17: no data2025-11-18: no data2025-11-19: no data2025-11-20: no data2025-11-21: no data2025-11-22: no data2025-11-23: no data2025-11-24: no data2025-11-25: no data2025-11-26: no data2025-11-27: no data2025-11-28: no data2025-11-29: no data2025-11-30: no data2025-12-01: no data2025-12-02: no data2025-12-03: no data2025-12-04: no data2025-12-05: no data2025-12-06: no data2025-12-07: no data2025-12-08: no data2025-12-09: no data2025-12-10: no data2025-12-11: no data2025-12-12: no data2025-12-13: no data2025-12-14: no data2025-12-15: no data2025-12-16: no data2025-12-17: no data2025-12-18: no data2025-12-19: no data2025-12-20: no data2025-12-21: no data2025-12-22: no data2025-12-23: no data2025-12-24: no data2025-12-25: no data2025-12-26: no data2025-12-27: no data2025-12-28: no data2025-12-29: no data2025-12-30: no data2025-12-31: no data2026-01-01: no data2026-01-02: no data2026-01-03: no data2026-01-04: no data2026-01-05: no data2026-01-06: no data2026-01-07: no data2026-01-08: no data2026-01-09: no data2026-01-10: no data2026-01-11: no data2026-01-12: no data2026-01-13: no data2026-01-14: no data2026-01-15: no data2026-01-16: no data2026-01-17: no data2026-01-18: no data2026-01-19: no data2026-01-20: no data2026-01-21: no data2026-01-22: no data2026-01-23: no data2026-01-24: no data2026-01-25: no data2026-01-26: no data2026-01-27: no data2026-01-28: no data2026-01-29: no data2026-01-30: no data2026-01-31: no data2026-02-01: no data2026-02-02: no data2026-02-03: no data2026-02-04: no data2026-02-05: no data2026-02-06: no data2026-02-07: no data2026-02-08: no data2026-02-09: no data2026-02-10: no data2026-02-11: no data2026-02-12: no data2026-02-13: no data2026-02-14: no data2026-02-15: no data2026-02-16: no data2026-02-17: no data2026-02-18: no data2026-02-19: no data2026-02-20: no data2026-02-21: no data2026-02-22: no data2026-02-23: no data2026-02-24: no data2026-02-25: no data2026-02-26: no data2026-02-27: no data2026-02-28: no data2026-03-01: no data2026-03-02: no data2026-03-03: no data2026-03-04: no data2026-03-05: no data2026-03-06: no data2026-03-07: no data2026-03-08: no data2026-03-09: no data2026-03-10: no data2026-03-11: no data2026-03-12: no data2026-03-13: 5.4 µg/m³2026-03-14: 11.3 µg/m³2026-03-15: 15.7 µg/m³2026-03-16: 16.9 µg/m³2026-03-17: 11.1 µg/m³2026-03-18: 3.7 µg/m³2026-03-19: 0.8 µg/m³2026-03-20: 1.6 µg/m³2026-03-21: 3.4 µg/m³2026-03-22: 1.5 µg/m³2026-03-23: 0.6 µg/m³2026-03-24: 0.4 µg/m³2026-03-25: 0.8 µg/m³2026-03-26: 1.6 µg/m³2026-03-27: 4.8 µg/m³2026-03-28: 11.2 µg/m³2026-03-29: 8.0 µg/m³2026-03-30: 10.9 µg/m³2026-03-31: 12.9 µg/m³2026-04-01: 22.4 µg/m³2026-04-02: 12.7 µg/m³2026-04-03: 12.9 µg/m³2026-04-04: 4.2 µg/m³2026-04-05: 4.1 µg/m³2026-04-06: 4.6 µg/m³2026-04-07: 6.9 µg/m³2026-04-08: 12.9 µg/m³2026-04-09: 24.1 µg/m³2026-04-10: 5.7 µg/m³2026-04-11: 12.3 µg/m³2026-04-12: 16.2 µg/m³2026-04-13: 19.6 µg/m³2026-04-14: 19.6 µg/m³2026-04-15: 16.9 µg/m³2026-04-16: 15.1 µg/m³2026-04-17: 24.1 µg/m³2026-04-18: 23.6 µg/m³2026-04-19: 14.6 µg/m³2026-04-20: 36.3 µg/m³2026-04-21: 7.2 µg/m³2026-04-22: 4.4 µg/m³2026-04-23: 5.6 µg/m³2026-04-24: 7.2 µg/m³2026-04-25: 5.9 µg/m³2026-04-26: 19.5 µg/m³2026-04-27: 3.9 µg/m³2026-04-28: 8.6 µg/m³2026-04-29: 30.3 µg/m³2026-04-30: 4.5 µg/m³2026-05-01: 7.2 µg/m³2026-05-02: 5.2 µg/m³2026-05-03: 8.0 µg/m³2026-05-04: 24.7 µg/m³2026-05-05: 13.9 µg/m³2026-05-06: 7.5 µg/m³2026-05-07: 4.0 µg/m³2026-05-08: no data2026-05-09: no data2026-05-10: no data2026-05-11: no data2026-05-12: no data2026-05-13: no data2026-05-14: no data2026-05-15: no data2026-05-16: 25.7 µg/m³2026-05-17: 10.0 µg/m³2026-05-18: 9.7 µg/m³2026-05-19: 10.0 µg/m³2026-05-20: 6.6 µg/m³2026-05-21: 7.7 µg/m³2026-05-22: 9.2 µg/m³2026-05-23: 11.5 µg/m³2026-05-24: 19.9 µg/m³2026-05-25: 23.9 µg/m³2026-05-26: 23.6 µg/m³2026-05-27: 24.7 µg/m³2026-05-28: 27.6 µg/m³2026-05-29: 26.3 µg/m³2026-05-30: 17.2 µg/m³2026-05-31: 12.5 µg/m³2026-06-01: 17.6 µg/m³2026-06-02: 16.9 µg/m³2026-06-03: 12.1 µg/m³2026-06-04: 11.6 µg/m³2026-06-05: 14.4 µg/m³2026-06-06: 13.9 µg/m³2026-06-07: 9.7 µg/m³2026-06-08: 11.7 µg/m³2026-06-09: 12.3 µg/m³2026-06-10: 11.9 µg/m³2026-06-11: 10.4 µg/m³2026-06-12: 13.1 µg/m³2026-06-13: 7.3 µg/m³2026-06-14: 14.3 µg/m³2026-06-15: 13.6 µg/m³2026-06-16: 14.6 µg/m³2026-06-17: 7.5 µg/m³2026-06-18: 8.6 µg/m³2026-06-19: 8.4 µg/m³2026-06-20: 11.3 µg/m³2026-06-21: 9.2 µg/m³2026-06-22: 18.0 µg/m³2026-06-23: 9.1 µg/m³2026-06-24: 5.6 µg/m³2026-06-25: 7.1 µg/m³2026-06-26: 5.0 µg/m³2026-06-27: 8.4 µg/m³2026-06-28: 8.2 µg/m³2026-06-29: 12.0 µg/m³2026-06-30: 10.4 µg/m³2026-07-01: 6.9 µg/m³2026-07-02: 3.2 µg/m³2026-07-03: 8.0 µg/m³2026-07-04: 9.4 µg/m³2026-07-05: 7.9 µg/m³2026-07-06: 7.1 µg/m³2026-07-07: 6.8 µg/m³2026-07-08: 7.5 µg/m³2026-07-09: 7.9 µg/m³2026-07-10: 17.7 µg/m³2026-07-11: 13.9 µg/m³2026-07-12: 7.4 µg/m³2026-07-13: 6.5 µg/m³2026-07-14: 12.3 µg/m³2026-07-15: 7.1 µg/m³2026-07-16: 2.1 µg/m³2026-07-17: 2.0 µg/m³2026-07-18: 0.1 µg/m³2026-07-19: 1.3 µg/m³2026-07-20: 5.5 µg/m³2026-07-21: 1.6 µg/m³2026-07-22: 10.2 µg/m³2026-07-23: 10.6 µg/m³2026-07-24: 16.2 µg/m³2026-07-25: 9.9 µg/m³2026-07-26: 1.6 µg/m³2026-07-27: 8.0 µg/m³2026-07-28: 8.3 µg/m³2026-07-29: 10.3 µg/m³2026-07-30: 13.1 µg/m³2026-07-31: 6.5 µg/m³2026-08-01: 4.9 µg/m³2026-08-02: 0.7 µg/m³2026-08-03: 4.1 µg/m³2026-08-04: 6.3 µg/m³2026-08-05: 2.2 µg/m³2026-08-06: 2.7 µg/m³2026-08-07: 2.1 µg/m³2026-08-08: 9.4 µg/m³2026-08-09: no data2026-08-10: no data2026-08-11: 7.9 µg/m³2026-08-12: 5.7 µg/m³2026-08-13: 4.6 µg/m³2026-08-14: 2.5 µg/m³2026-08-15: 4.8 µg/m³2026-08-16: 2.7 µg/m³2026-08-17: 4.1 µg/m³2026-08-18: 4.8 µg/m³2026-08-19: 3.3 µg/m³2026-08-20: 2.4 µg/m³2026-08-21: 8.9 µg/m³2026-08-22: 7.3 µg/m³2026-08-23: 3.6 µg/m³2026-08-24: 4.9 µg/m³2026-08-25: 4.6 µg/m³2026-08-26: 1.6 µg/m³2026-08-27: 2.4 µg/m³2026-08-28: 2.4 µg/m³2026-08-29: 1.7 µg/m³2026-08-30: 2.3 µg/m³2026-08-31: 2.5 µg/m³2026-09-01: 3.4 µg/m³2026-09-02: 7.0 µg/m³2026-09-03: 5.7 µg/m³2026-09-04: 7.2 µg/m³2026-09-05: 24.9 µg/m³2026-09-06: 17.2 µg/m³2026-09-07: 7.4 µg/m³2026-09-08: 8.7 µg/m³2026-09-09: 145.0 µg/m³2026-09-10: no data2026-09-11: no data2026-09-12: 12.7 µg/m³2026-09-13: 38.3 µg/m³2026-09-14: 25.0 µg/m³2026-09-15: no data2026-09-16: no data2026-09-17: 231.9 µg/m³2026-09-18: 53.9 µg/m³2026-09-19: 26.6 µg/m³2026-09-20: 12.3 µg/m³2026-09-21: 309.7 µg/m³2026-09-22: 43.8 µg/m³2026-09-23: 51.0 µg/m³2026-09-24: 5.1 µg/m³2026-09-25: 6.4 µg/m³2026-09-26: 24.7 µg/m³2026-09-27: 7.3 µg/m³2026-09-28: 42.3 µg/m³2026-09-29: 8.2 µg/m³2026-09-30: 30.3 µg/m³
42 of 188 measured days were over the WHO 24-hour guideline (15 µg/m³). One row per month, one square per local day.
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Last 4 days, hour by hour

152412026-10-01 00:00 UTC: 22.3 µg/m³2026-10-01 01:00 UTC: 72.4 µg/m³2026-10-01 02:00 UTC: 162.4 µg/m³2026-10-01 03:00 UTC: 178.4 µg/m³2026-10-01 04:00 UTC: 203.3 µg/m³2026-10-01 05:00 UTC: 185.9 µg/m³2026-10-01 06:00 UTC: 93.4 µg/m³2026-10-01 07:00 UTC: 63.8 µg/m³2026-10-01 08:00 UTC: 241.1 µg/m³Sep 28Sep 29Sep 30Oct 1
Times in UTC. Dashed line: WHO 24-hour guideline (15 µg/m³).

Its world rank, day by day

#1#2372AprMayJunJulAugSep
Rank on each day's board (1 = most polluted city that day).

2026 against 2025, month by month

15JanFebMar 2026: 6.5 µg/m³MarApr 2026: 13.5 µg/m³AprMay 2026: 14.6 µg/m³MayJun 2026: 11.1 µg/m³JunJul 2026: 7.6 µg/m³JulAug 2026: 4.0 µg/m³AugSep 2026: 44.5 µg/m³SepOctNovDec
Faded bars: 2025. A month shows once it has 10 measured days.

Monitors

StationOperatorType
Lycée Technique André Peytavin, Saint-LouisCC BY 4.0kaikai.devLow-cost
Saint Louis, Ecole Moussa DiopCC BY 4.0kaikai.devLow-cost
Saint Louis, Cem guinaw railleCC BY 4.0kaikai.devLow-cost

No reference monitor here, so the value is the median of low-cost sensors (at least two reporting each hour). Low-cost sensors can read high in humid air. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.

Other cities in Senegal

30-day averages, µg/m³. All of Senegal.

Updated 2026-10-01 18:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.